There are a spectrum of dermatological disorders and conditions that are commonly treated with a topically applied agent. In some treatments, the agent offers a therapeutic purpose, for example for treating or ameliorating psoriasis, eczema or dermatitis. In other treatments, the agent offers a cosmetic or protective effect, such as a skin lightening agent or depigmenting agent or a sun protective agent. Topical application of agents for cosmetics and medical purposes has certain limitations. For example, the applied agent can be swept off easily from the skin or the formulation in which the agent is applied can include chemicals that may interfere with the balance of the natural skin microbiota. Creams and ointments can be messy, greasy, cumbersome, and patients can only treat a limited number of lesions on a limited area, and only on certain anatomic sites. As a result, nearly 35% of prescriptions for topical preparations remained behind the pharmacy counter, the patient opting to not pick up the topical prescription. In contrast, prescriptions for systemic agents fared much better, with reports that only 14% went unredeemed (Storm, A. et al., J. Am. Acad. Dermatol., 59:27-33 (2008)).
There are also disadvantages with topical treatments in terms of the patient understanding of how often and how much to apply. In the case of sunscreens, as just one example, people typically apply sunscreens less than half as thickly as and less often than recommended, thus compromising their protection substantially (Stern, R. S., N Engl J. Med, 350:1526-1534 (2004)).
There remains a need for more effective topical treatment compositions, for medical, cosmetic and preventative purposes. By way of example, the need for more effective UV protection is recognized around the world, as it is the main cause for the increasing incidence of skin cancers and photoaging. By way of another example, topical treatment of psoriasis and eczema, and other skin disorders, with an effective, long-term therapy is needed.
Healthy human epidermis is colonized by thousands of bacterial species, including bacterial members from mainly five orders harboring about 60% of the total skin microbiome in all people. A healthy human epidermis is colonized with trillions of bacterial cells, creating, on average, approximately 108 bacteria per square centimeter. The skin microflora has evolved into commensal relationship with the host, as they exploit the unique attributes of the skin and keep the skin ecosystem in a healthy balance (Grice A. E., Science, 324: 1190-1192 (2009). A therapy that uses skin bacteria for different dermatological needs would be able to maintain the natural ecosystem of the skin, and also enhance those natural skin bacteria to address specific dermatological needs.
The use of probiotic micro-organisms for improving the skin's immune function under stress conditions, leading to immune suppression, specifically for normalizing the skin's immune activity and reducing the tendency to develop hyper-reactions under such conditions is described in the art, for example in EP Patent No. 1322318. Cosmetic use of probiotic microorganisms as an active agent useful for treating and/or preventing impairing radiance of the skin complexion has also been described (US2012/0301452). Use of solely probiotics, is one approach for topical skin treatments, yet there remains a need for a longer term and/or more potent approach.
Transformed bacteria are being used intensively in modern biotechnology for the production of recombinant proteins and various molecules for food, pharmaceutical, and biocatalysis applications. Bacteria able to produce and secrete proteins encoded by heterologous genes are used extensively for the industrial production of pharmaceutical proteins such as human and animal growth hormones, insulin, interferons, cytokines etc. Organisms other than E. coli thus far used or proposed for industrial production include cultured mammalian and insect cells, yeasts and fungi, and various bacteria species, including a number of Bacillus spp. Among the bacteria already widely used for industrial purposes are the lactic acid bacteria, which are employed as starter cultures for fermented foodstuffs, and as flavor enhancers, and preservatives. These properties depend on the ability of these organisms to produce certain enzymes, lactic acid and harmless antimicrobial polypeptides, such as nisin (see, for example. U.S. Pat. No. 6,221,648).
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.